(CNN) --From the fields of Normandy to the forests of Ardennes, battlefields around the globe have healed their wounds and nature has fought back.

Nowhere is this more evident than in the heavily-fortified border zone between North and South Korea. The Demilitarized Zone, or DMZ as it is more popularly known is now one of the few untouched havens for Northeast Asia's wildlife.

Some say the only threat to its survival is peace.

"Scientists have done a pretty good job of studying biodiversity in South Korea since the 1950's and I am confident that there is no place like the DMZ on the peninsula," Ke Chung Kim of the DMZ Forum told CNN.

The zone was established at the end of the three-year Korean War in 1953 and while intensive agriculture and industrialization has ravaged both the North and South since, tight security measures have left the environment in the DMZ largely undisturbed for the last 50 years.

As a result, the ribbon of untouched land along the 38th parallel has now become an important refuge for two of the world's most endangered birds: the white-naped and the red-crowned crane.

Other rare species include Asiatic black bears, Chinese gorhals and egrets.

According to some accounts there may even be Korean tigers in the DMZ -- a sub-species of the Siberian tiger, one of the rarest tigers on the planet.

In total more than 20,000 migratory fowl utilize the border area. They manage to avoid setting off land mines -- although nowadays some may be too old to be active.

The 4-kilometer-wide by 250-kilometer long (2.5 miles by 155 miles) DMZ stretches across the entire width of the Korean Peninsula, encompassing a cross section of ecosystems and landscapes.

The corridor follows the Military Demarcation Line established by the 1953 Armistice Agreement between the two Koreas -- which are still technically at war.

After the fall of the Berlin wall in 1989 the DMZ is the last remaining Cold War-style frontier on the planet, bristling with sensors, tank traps and automatic artillery.

Up to two million soldiers guard the world's most heavily fortified border, whilst listening to the sound of crested shell ducks and swan geese.

"The DMZ and its adjacent Civilian Control Zone are unique containing wetlands, forests, estuaries, mountains, coastal islands, riparian valleys and agricultural fields," says Hall Healy of Facilitated Solutions International, an organization that aids conservation groups working in the border area.

Biodiversity and barbed wire

In the event of a formalized peace breaking out between the two Koreas any biological reserve would compete with other proposals for the land, even though the South Korean government has said the DMZ is a priority ecosystem.

While poverty alleviation would likely prevent North Korea from putting much weight on nature conservation in the DMZ, for its southern neighbor it would be the prospect of further economic development and integration with the North that would be a driving force for development.

Yet pressure from the DMZ Forum, DMZ Vets and the Korean Federation for Environmental Movement (KFEM) to declare the area a "biodiversity zone," has been growing.

Since much of the natural Korean natural habitat has been degraded by industrialization, urbanization and agriculture, conservationists hope that the DMZ will be preserved for its beauty and significance.

"South Korea's habitats have been exploited many times over and North Korea's environmental conditions are dismal at best," says Kim.

"North Korean environmental demise is the result of persistent mismanagement of forests, military destruction, and poverty," he says.

In the South, the picture is not much better.

A 1994 biodiversity study revealed that almost 30 percent of the country's mammals, 48 percent of reptiles and 60 percent of amphibians are either extinct or endangered.

The peninsula, which covers a combined area the size of Pennsylvania and New York State, already has a combined population of about 70 million, which could rise to 100 million by 2025.

This is putting more pressure on the area to the north of Seoul and to the south of Pyongyang, the North Korean capital.

The distance between the two cities is only 194 kilometers and every month, development creeps nearer to the demilitarized zone.

"Similar flora and fauna may have existed in other locations before, but due to development, these locations are now highly fragmented and do not possess the diversity of species they once did," says Healy.

Many conservationists see the DMZ as a ready-made nature reserve.

It is already well defined and controlled by a body separate to both countries -- the Military Armistice Commission.

Only the future will tell. At present the conservationists best bet is for the barbed wire to stay in place to keep the developers out and the wildlife intact.